1. Field
Embodiments relate to an organic light emitting display and a method of driving the same, and more particularly, to an organic light emitting display capable of controlling a voltage in accordance with a temperature change and a method of driving the same.
2. Description of the Related Art
Recently, various flat panel displays (FPD) capable of reducing weight and volume relative to cathode ray tubes (CRT) have been developed. The FPDs include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting display.
Among the FPDs, organic light emitting displays display an image using organic light emitting diodes (OLED) that generate light by re-combination of electrons and holes generated to correspond to the flow of current. Organic light emitting displays are widely used in numerous products, e.g., a personal digital assistant (PDA), an MP3 player, a mobile telephone, and so forth, due to various advantages, such as excellent color reproducibility and small thickness.
FIG. 1 illustrates a circuit diagram of a pixel adopted by a common organic light emitting display. Referring to FIG. 1, the pixel is coupled to a data line Dm and a scan line Sn, and includes a first transistor M1, a second transistor M2, a capacitor Cst, and an organic light emitting diode OLED.
The first transistor M1 has a source coupled to a first power source ELVDD, a drain coupled to an anode electrode of the OLED, and a gate coupled to a first node N1. The second transistor M2 has a source coupled to the data line Dm, a drain coupled to the first node N1, and a gate coupled to the scan line Sn. The capacitor Cst has a first electrode is coupled to the first power source ELVDD and a second electrode coupled to the first node N1. The OLED has an anode electrode coupled to the drain of the first transistor M1 and a cathode electrode coupled to a second power source ELVSS.
In the pixel having the above structure, the voltage of the first node N1 is determined to correspond to the data signal transmitted through the data line Dm. In accordance with the voltage of the first node N1, in the first transistor M1, current flows from the first power source ELVDD to the second power source ELVSS. Due to the above operation, the OLED emits light.
In the OLED adopted by the above pixel, current flows by the first power source ELVDD and the second power source ELVSS. The driving margin of the second power source ELVSS is determined in accordance with the current that flows at a low temperature.
However, organic light emitting displays are not always driven at the low temperature. When the voltage of the second power source ELVSS due to the driving margin set at the low temperature is used at a room temperature, the voltage of the second power source ELVSS is set to be lower than necessary, increasing power consumption.